Chapter 6.3 Flashcards
What is the general characteristic of capacitors
- their general characteristic is to hold charge at a particular voltage
- > eg; defibrillator, or lightning
What is the capacitance of a capacitor defined as?
-it is defined as the ratio of the magnitude of charge stored on one plate to the potential difference across the capacitor
Does a uniform electric field exist between a parallel plate capacitor?
-yes it does
What happens to the capacitance when a dielectric material is introduced between the plates of a capacitor?
-the capacitance increases by a dielectric constant(K)
What is the dielectric constant
- it is a measure of the materials insulating ability
- >note a vacuum has a dielectric constant of 1
What happens to the voltage when a dielectric material is placed in an isolated charged capacitor. Note here the charged capacitor is disconnected from any circuit
- the voltage across capacitor decreases
- > because the dielectric material shielding the opposite charges from each other
-increase in capacitance due to dielectric material= decrease in voltage
What happens to the voltage when a dielectric material is placed in a charge capacitor within a circuit. Note here the charged capacitor
- when a dielectric material is introduced
- > the increase in capacitance arises from an increase in stored charge
- > the voltage remains constant because it is equal to the voltage source
How can stored energy in a capacitor be discharged
-charge can be discharged across plates or through some conductive material with which the plates are in contact with
Why does capacitance for capacitors decrease when they are in series. What happens to the capacitance for capacitors in series
- because the capacitors must share the voltage drop in the loop and cannot store as much charge
- in parallel, the capacitance increases
